A well-calculated fluid supply assembly of this purpose is disclosed in U.S. Pat. No. 4,643,442. In this prior art assembly, the cylinder head of a cylinder case of the hydraulic lift cylinder includes at its front surface a vertical seating surface on which one or more control valve assemblies for fluid-operated auxiliary implememts are mounted. For meeting the circumstances that the number of auxiliary implements to be equipped is often changed in accordance with a specific design of the working vehicle, the control valve assemblies are fashioned as a stack valve in which control valve assemblies of the number corresponding to that of auxiliary implements are successively integrated on the front of the cylinder head such that fluid output ports of the valve assemblies open upwards. A cover is attached to the front of such one or more control valve assemblies. This cover includes a fluid input port to be connected to a hydraulic pump and a fluid output port to be connected to a power steering mechanism such that these ports open forwards. The cover further includes a flow divider which divides inflow supplied to the fluid input port into two flows so that fluid supplied by a single pump can be used for operating the power steering mechanism and for operating fluid-operated auxiliary implements and hydraulic lift cylinder. One of the output flows of the flow divider is directed to the fluid output port for the power steering mechanism, while the other output flow of the flow divider is directed into the control valve assemblies. The latter output flow is further directed into the cylinder head and then to the control valve assembly for the hydraulic lift cylinder.
In this fluid supply assembly, the cylinder head of hydraulic lift cylinder is skillfully used for the purpose of providing valves for operating three or more fluid-operated devices including hydraulic lift cylinder and power steering mechanism by fluid fed by a single pump in a compact fashion. However, there remain certain problems.
Firstly, the fluid supply assembly set forth above is fashioned on the assumption that a working vehicle is necessarily equipped not only with an auxiliary implement, such as a rotary tiller or rear-mount mower, to be connected liftably to and to be drawn by the vehicle but also with at least one more auxiliary implement such as a front loader, snow-removing implement or bulldozing implement to be eqipped at a front of the vehicle or mid-mount mower. However, some working vehicles are of a design in which only an auxiliary implement to be connected liftably to the vehicle is to be equipped. The fluid supply assembly set forth above does not permit employment of valves of a same fundamental structure also in such vehicles for enhancing economy.
Secondly, the cover including two fluid ports set forth above is shifted in position in a londitudinal direction of the vehicle when the number of control valve assemblies is changed in accordance with a change in number of fluid-operated auxiliary implements. Consequently, positions of the fluid input port to be connected to a pump and fluid output port to be connected to a power steering mechanism are also changed in the same direction. From this, fluid pipings of different designs are required even between vehicles which are identical with one another in the vehicle structure itself and are different only in number of fluid-operated auxiliary implements to be equipped.
Further, valve assemblies integrated successively in the longitudinal direction of the vehicle will require to disassemble all of them even when one of them is exchanged for another one or even when one valve assembly is added or removed. In addition, although the fluid output ports of valve assemblies opening upwards and pipings connected thereto are well covered or protected by a seat which is usually disposed above a rear portion of a working vehicle, metal pipes generally used for such fluid pipings will require a certain vertical interval between the valve assemblies and seat so that level of the seat will sometimes be heightened unduly for a working vehicle used in orchards or the like.
Accordingly, a primary object of the present invention is to provide a novel fluid supply assembly having a fundamental structure which makes the assembly applicable also to a working vehicle to be equipped with only an auxiliary implement to be connected liftably to the vehicle.
An attendant object of the invention is to provide a novel fluid supply assembly which assures a compactness of the assembly.
Another attendant object is to provide a fluid supply assembly into which a control valve means for a fluid-operated auxiliary implement can be incorporated with ease while permitting use of pipings of the same design for feeding fluid from a pump to the assembly and for supplying fluid from the assembly to a power steering mechanism.
A further object of the present invention is to provide a fluid supply assembly in which a control valve means is arranged in a way not requiring an undue heightening of a seat.
A still further object of the invention is to provide a fluid supply assembly to which, in addition to a control valve means for a fluid-operated auxiliary implement, one or more control valve means can be added with ease.